#include "Heap.h"

void HPInit(HP* php)
{
	assert(php); 
	php->a = NULL;
	php->capacity = php->size = 0;
}
void HPDestory(HP* php)
{
	assert(php);
	free(php->a);
	php->a = NULL;
	php->capacity = php->size = 0;
}
void Swap(HPDataType* a, HPDataType* b)
{
	HPDataType tmp = *a;
	*a = *b;
	*b = tmp;
}
void AdjustUp(HPDataType* a,int child)
{
	int parent = (child - 1) / 2;
	while (child>0)
	{
		if (a[child] < a[parent])
		{
			Swap(&a[child], &a[parent]);
			child = parent;
			parent = (parent - 1) / 2;
		}
		else
		{
			break; 
		}
	}
}
void HPPush(HP* php, HPDataType x)
{
	assert(php);
	if (php->capacity == php->size)
	{
		int newcapacity = php->capacity == 0 ? 4 : php->capacity * 2;
		HPDataType* tmp = (HPDataType*)realloc(php->a, sizeof(HPDataType) * newcapacity);
		if (tmp == NULL)
		{
			perror("realloc fail");
			return -1;
		}
		php->a = tmp;
		php->capacity = newcapacity;
	}
	php->a[php->size] = x;
	php->size++;

	AdjustUp(php->a, php->size - 1);
}
HPDataType HPTop(HP* php)
{
	assert(php);
	assert(php->size > 0);
	return php->a[0];
}
void AdjustDown(HPDataType* a, int n, int parent)
{
	int child = parent * 2 + 1;
	while (child<n)
	{
		if (child+1<n&&a[child + 1] < a[child])
		{
			++child;
		}
		if (a[child] < a[parent])
		{
			Swap(&a[child], &a[parent]);
			parent = child;
			child = parent * 2 + 1;
		}
		else
		{
			break;
		}
	}
}
void HPPop(HP* php)
{
	assert(php);
	assert(php->size > 0);
	Swap(&php->a[0], &php->a[php->size - 1]);
	php->size--;

	AdjustDown(php->a, php->size, 0);
}
bool HPEmpty(HP* php)
{
	assert(php);
	return php->size == 0;
}